This is a new development different from my previous invention U.S. Pat. No. 6,722,322 by the title “Internal Combustion engine”, and having an important improvement of making the return movement of the piston after combustion is free from engaging with the mechanism of the axle. This improvement allows an internal combustion engine to run more simple and efficient and also increases flexibility for engine making designs, wherein my previous invention of U.S. Pat. No. 6,722,322 or conventional internal combustion engine is complicated and inefficient in comparison to this invention for their pistons are engaged with mechanism required further combustions for returns.
Internal combustion engines are widely used as power plants for many equipment and apparatuses such as automobiles, power generators, pumps, compressors, ships, tractors, machines, and aeroplanes. In order to supply adequate power, conventional internal combustion engines are generally formed by connecting a plurality of alternately combusting cylinders together. Each cylinder of an internal combustion engine generally includes a hollow combustion chamber inside which there is disposed a linearly and reciprocally moveable piston member.
In general, the piston is driven towards the cylinder head, which is usually the ceiling of a cylinder, to compress the gaseous fuel mixture introduced into the cylinder during one part of the engine cycle. The subsequent timely combustion of the compressed fuel causes an explosion to drive the piston away from the cylinder head. This movement also drives the connecting power transmission mechanism to deliver the resulting mechanical power outside of the cylinder for the intended use.
In general, 1) fuel intake, 2) compression, 3) combustion and 4) exhaustion are the typical steps involved in a complete engine operation cycle steps of a conventional four-stroke internal combustion engine. Because an engine cylinder must withstand the enormous explosive force during the engine operating cycles, internal combustion engines are typically made of steel, wrought iron or other ferrous or non-ferrous metal alloys which are inherently heavy and bulky. Since a plurality of engine cylinders are usually connected together to provide sufficient power output as well as for smooth engine operation, the weight of engines becomes an important factor to negotiate if to improve the efficiency of an engine is to be improved. In general, engine designers endeavour to minimize the engine weight-to-power output ratio, or, alternatively, to maximise the power-to-weight ratio per combustion cylinder. Also, in a multi-cylinder engine, usually only one cylinder delivers power at a time which means that the instantaneous power generating engines must also drive the remaining non-power generating pistons and the connecting mechanism. Therefore, it will be beneficial if the connecting mechanism or parts between cylinders can be minimized for a given set of cylinders.
For example, U.S. Pat. No. 6,318,309 describes an internal combustion engine in which two pistons are reciprocatively disposed in each cylinder thereby forming combustion chamber between the pistons. However, two sets of rather complicated piston connecting rods are required and a third piston is responsible for a specific combustion chamber area not served by the other pistons. U.S. Pat. No. 3,010,440 teaches another example of an internal combustion engine having more than one piston disposed in a single cylinder in which each piston covers its own combustion chamber which is not served by the other piston. These patents and other conventional internal combustion engines have their pistons and engine mechanism engaged mechanically together without any free return movement for the pistons, or, at least not the same as in this invention.
Most conventional internal combustion engine can consume only one fuel, especially fossil fuel, and is dramatically influenced by its market price. It is beneficial to provide an internal combustion engine able to consume two fuels at a time for one regular fuel with other one economical or environmental fuel.
In a conventional four-stroke cycle internal combustion engine, the complete engine operating cycle of fuel intake, compression, combustion and exhaust requires two cycles of linearly reciprocal motion of the piston member. In other words, the piston member has to move up and down twice in order to complete a single engine cycle. Since the engine cycle involving fuel combusting piston is the only power generating part of the cycle, the other piston is non-power generating but power consuming, noting that the piston is usually always connected the an external load. Hence, it will be highly beneficial if combustion of every cylinder is independent to each other for delivery of power without engaging each other mechanically for wasting energy. There are provided in this invention an improved internal combustion engine or engine topology which can overcome or at least mitigate the short-comings associated with the afore-said disadvantages of conventional internal combustion engine.